Crunchzilla is a free, web-based coding site consisting of three levels. Code monster is for preteens, Code Maven is for teens & adults, and Game Maven is the most difficult level for those 16+.
The site works by selecting your level and following the directions in the speech bubble. Code goes in the left box, while the output of the code shows up in the right box. Clicking on the speech bubble takes you to the next set of directions.
Below the code are a few links, the most important is the Lessons Sections. This allows students to jump to a specific lesson. Since the site doesn’t have any saves or accounts, this is pretty important.